While many strategies tend to be problem-dependent, there are a few which are generally applicable to bioelectric field problems and worth mentioning. One general technique for dealing with the problem of nonuniqueness transfers the problem to be solved into a model problem. Here, one usually breaks up the solution domain into a finite number of subdomains. In each subdomain, one describes a simplified model of the actual bioelectric source (such as a dipole). The problem then becomes to find the magnitude and direction of each of the simplified sources in the subdomains (as opposed as to having to find the locations of the actual sources, plus their magnitudes). Other methods work to limit the space of the solution domain [15] so that one can perhaps pick out solutions which are the only physiologically feasible ones.